suicide disclose their ideation or intent to those around them, according to one meta-analysis (Cavanagh et al., 2003). These studies have one critical limitation, however: The definitions of ideation and intent vary, leading to variations in prevalence. One of the most recent and thorough review articles found that 75 percent of those who subsequently die by suicide visited their primary care provider in the last year of life and 45 percent in the last month (Luoma et al., 2002).
An easy conclusion from these findings is that more attention should be given to suicidal ideation and threats. However, the major problem is that expressions of ideation or threats are highly common. A large, nationally representative survey of U.S. adults found that 15 percent of them report seriously considering suicide at some point in their life (Nock et al., 2009a). Approximately one-third of those who think about suicide at some point in their life later make a suicide attempt. Narrowing the time frame to the past 12 months, 15 percent of ideators proceed to make a suicide attempt (Nock et al., 2009a). What these findings suggest is that it is exceedingly difficult to identify from the large number of ideators the small percentage of those who will progress to a suicide attempt. While suicide has general risk factors, as well as chronic versus short-term risk factors, no combinations of risk factors currently have sufficient sensitivity and specificity to predict who among the groups at risk will make an attempt or completion, under what circumstances, and at what time (Goodwin and Jamison, 2007).
One surprising finding mentioned by Nock was that depressed people with suicidal ideation, although a risk group, were not the leading group at risk for progression to a suicide attempt. Ideators with anxiety disorders and disorders of impulse control, such as conduct disorder and posttraumatic stress disorder, exceeded depression in their predictive power for making suicide attempts, according to a large, nationally representative epidemiology study of U.S. adults, the National Comorbidity Survey Replication (Nock et al., 2009a, 2009b). Having an anxiety disorder is an independent risk factor for suicidal ideation and suicide attempts. Anxiety and mood disorders, when comorbid, heighten the risk as compared with a mood disorder alone, according to a prospective, population-based study of adults in the Netherlands (Sareen et al., 2005).
Two new alternatives to the general measure “suicidal ideation” show promise: real-time, electronic monitoring systems of suicidal thinking and behavior at different time points, and a new psychometric measure asking patients to rate suicidal intention “at its worst point in time.”